>> ---------------------------------------------------------
>> "It's the early bird that fits the bill"
>> BIRDS with modern-looking beaks appeared on the evolutionary scene
>> much earlier than palaeontologists had thought. Beaks were not
>> supposed to have evolved until 75 million years after Archaeopteryx,
>> the earliest known bird. Now researchers say that some avian species
>> had evolved proper beaks just a few million years after Archaeopteryx
>> made its debut.
>> In this week's issue of Nature (vol 377, p 616), Lian-hai Hou and
>> Zhonghe Zhou of the Institute of Vertebrate Palaeontology and
>> Palaeoanthropology in Beijing and their colleagues describe three
>> partial skeletons of a bird they call Confuciusornis. The fossils
>> come from ancient lake sediments near China's border with Korea.
>> These deposits are difficult to date accurately, but the researchers
>> believe that Confuciusornis lived about 10 million years after
>> Archaeopteryx, which appeared around 145 million years ago.
>> In most respects, Confuciusornis is similar to Archaeopteryx. For
>> example, its wings bear long claws, which were probably used to
>> scramble up trees. But unlike Archaeopteryx, Confuciusornis does not
>> have teeth. "It has a horny bill, just like a modern bird," says
>> Larry Martin of the University of Kansas in Lawrence, who worked with
>> the Chinese researchers. The oldest billed bird discovered previously
>> Gobipteryx, lived in Mongolia about 70 million years ago.
It's worth noting that Martin *may* have a bias towards evidence that
would indicate an older (than mid-Jurassic) age for birds. He is well
known as one of the hold-outs against the idea of a dinosaurian origin
for birds. (I think he is in favor of a more crocodilian-type ancestor
for birds; yes, I know that sounds silly; no, I don't agree with it)
>> (Peter Aldhous, "It's the early bird that fits the bill", New
>> Scientist, 21 October 1995, p19)
>> ---------------------------------------------------------
>> If birds with beaks existed "just a few million years after
>> Archaeopteryx made its debut", then if evolutionists wish to maintain
>> that Archaeopteryx is a transitional form between reptiles and birds,
>> it seems they must postulate either: a) a very rapid transformation
>> of teeth into a beak; or b) assume that Archaeopteryx dates from
>> further back in the fossil record.
The "few million years" is really 10 million years, which seems to be to
be ample time to evolve a beak. Having the teeth disappear seems pretty
easy, developing a beak sounds a bit more difficult, although I know
nothing about beaks. Embryology may tell scientists how beaks develop,
but I'll have a guess and say that it may have evolved from keratin,
just like our fingernails or a rhino's horn.
>> The problem for evolution with a) is finding a naturalistic
>> evolutionary mechanism that can transform a full set of teeth into a
>> beak in "just a few million years". OTOH, the problem with b) is it
>> might push Archaeopteryx back too far before its putative dinosaur
>> ancestors, and to where there is no fossil evidence. Of course if it
>> is supposed that Archaeopteryx existed much earlier than the fossil
>> record indicates, then one could claim the same for Confuciusornis!
Although Archaeopteryx is considered a superb example of a reptile-bird
intermediate, I have heard claims that it is *not* considered to be a
direct ancestor of all later birds (I do not know why). Archae and this
new find could have a somewhat older common ancestor.
>> Also, if an "advanced characteristic" such as a beak, was naturally
>> selected because it had survival value, then "subsequently died out"
>> (presumably because it had lost survival value), it strains
>> credibility and believe the same feature was again re-selected
>> because once more it had survival value!
This is an over-simplification of evolutionary theory. Assuming the
beak evolved for some survival value, the later extinction of some
branches doesn't tell us anything about the beak; it could have happened
for many other reasons (e.g. disappearing food source).
>> Please note that as a Progressive Creationist, I do not necessarily
>> deny that the bird archetype is a variation on a reptilian theme, but
>> I am sceptical that a plausible naturalistic evolutionary mechanism
>> could produce the result in the shortening time available.
Hang on, we're talking *10 million years*, almost twice the time it is
thought to have taken humans to evolve from apes. Evolving a beak seems
a trivial change, compared to that. Our sampling density (two species,
in tens of millions of years) can hardly be expected to give us a good
handle on the fine details of the evolution of birds.
This new find sounds like strong support for evolution, not evidence
against it. We've got a new bird, a bit younger and a bit more modern
looking than the oldest known bird.
-- Jim Foley Symbios Logic, Fort Collins, COJim.Foley@symbios.com (303) 223-5100 x9765 I've got a plan so cunning you could put a tail on it and call it a weasel. -- Edmund Blackadder